Sanitary napkin having components capable of separation in use

ABSTRACT

A disposable absorbent article, such as a sanitary napkin, is disclosed that has components which may separate in the Z-direction with relation to other components of the article when the absorbent article is worn. The sanitary napkin of the present invention comprises a liquid pervious topsheet, a liquid impervious backsheet, an absorbent core positioned between the topsheet and the backsheet, and a liquid pervious spacing structure for moving the topsheet away from the core. The spacing structure is generally positioned between the topsheet and the core. The spacing structure has a longitudinal centerline, and opposed lateral sides which may move inwardly toward the longitudinal centerline when the spacing is compressed from the sides. This results in at least a portion of the spacing structure moving the topsheet apart from the absorbent core. In an alternative embodiment, the sanitary napkin of the present invention also has an absorbent core which separates from the backsheet of the sanitary napkin.

This is a continuation of application Ser. No. 08/386,607, filed on Feb.10, 1995 (now abandoned), which was a continuation of application Ser.No. 08/203,912, filed on Feb. 28, 1994 (now abandoned) which was adivisional application of application Ser. No. 07/892,393, filed on May28, 1992 (now U.S. Pat. No. 5,324,278), which was a continuation ofapplication Ser. No. 07/605,583, filed on Oct. 29, 1990 (now abandoned).

FIELD OF THE INVENTION

The present invention relates generally to disposable absorbent articlessuch as sanitary napkins worn by women, and more particularly tosanitary napkins that have components capable of separation in use toprovide improved contact of the sanitary napkin with the wearer's bodyand increased protection from soiling of the wearer's undergarments.

BACKGROUND OF THE INVENTION

Absorbent articles such as sanitary napkins, pantiliners, andincontinent pads are designed to absorb and retain liquid and otherdischarges from the human body and to prevent body and clothing soiling.It has been found to be desirable to attempt to create absorbentarticles, such as sanitary napkins, that maintain contact with the bodyof the wearer when they are worn. It is even more desirable thatsanitary napkins also conform as closely as possible to the body of thewearer. Such a body-conforming capability is believed to increase theeffectiveness of the sanitary napkin by reducing the possibility thatmenses will travel around the perimeter of the sanitary napkin and leak.

There have been a number of recent efforts to provide sanitary napkinsand other absorbent articles with improved body-conformingcharacteristics. Two recent efforts are described in U.S. Pat. No.4,950,264, issued to Osborn, III, on Aug. 21, 1990, and U.S. patentapplication Ser. No. 07/175,817 entitled "Absorbent Article" filed Mar.31, 1988 in the name of Kenneth Barclay Buell, both of which areincorporated by reference herein. While the sanitary napkins disclosedin these references work quite well, the search for new and differentways of improving body contact has continued.

It is especially desirable that sanitary napkins maintain contact withand conform to the body of the wearer under dynamic conditions (when thewearer walks, sits, etc.). There are certain critical dynamic conditionswhich stress the sanitary napkin and tend to reduce its ability to stayin contact with the body of the wearer. As soon as the sanitary napkinis put on, for instance, the sanitary napkin is subjected to lateralcompression by the upper portions of the wearer's thighs. The forcesapplied by the wearer's thighs generally tend to distort the shape ofthe sanitary napkin, reducing the size of the target the sanitary napkinprovides.

One attempt to control the effect of these compressive forces isdisclosed in UK Patent Application 2 168 612 A, published Jun. 25, 1986.The UK patent application discloses a sanitary towel with a resilientinsert positioned within the core or adjacent to a face of the core thatis intended to inhibit permanent distortion of the towel. The insertonly serves to resist deformation of the sanitary towel, however, itdoes not utilize the compressive forces to improve contact of the towelwith the wearer's body. Further, the UK patent application does notteach or disclose utilizing the compressive forces to provide thesanitary towel with body-conforming properties.

In addition, as is well known, sanitary napkins are generally fastenedto the wearer's undergarments by a pressure sensitive adhesive or othermeans. The means is stressed when the wearer moves about, because thewearer's undergarments may not move in concert with the body of thewearer, and the sanitary napkin may not flex and twist with the wearer'sundergarments. If stressed excessively, the pressure sensitive adhesive,or other means may become detached from the undergarment. This willcause the sanitary napkin to shift from the desired position andregistration with the wearer's vaginal opening. It is, therefore, alsodesirable to provide the body-conforming sanitary napkin with amechanism to accommodate the independence of movement between the bodyof the wearer and the wearer's undergarments.

It is, therefore, an object of this invention to provide an absorbentarticle, such as a sanitary napkin, which readily intercepts menses whendischarged by maintaining contact with and conforming to the shape ofthe female urogenital and buttocks region.

It is also an object of this invention to provide a sanitary napkinwhich maintains contact with the wearer throughout the range of normalmovements encountered while the sanitary napkin is worn. It is alsodesirable that the sanitary napkin continue to maintain contact with thewearer's body when it is subjected to the forces that normally accompanythe wearing of a sanitary napkin.

It is another object of the present invention to provide a sanitarynapkin that advantageously utilizes the compressive forces exerted bythe wearer's thighs to improve the contact between the sanitary napkinand the wearer's body.

It is another object of the present invention to provide a sanitarynapkin that has body-contacting and body-conforming components that donot have any sharp corners, edges, or fold lines that would irritate thewearer.

Finally, it is an object of this invention to provide a sanitary napkinwith a mechanism to accommodate the independence of movement between thebody of the wearer and the wearer's undergarments.

These and other objects of the present invention will be more readilyapparent when considered in reference to the following description andwhen taken in conjunction with the accompanying drawings.

SUMMARY OF THE INVENTION

The present invention is an absorbent article, such as a sanitarynapkin. The sanitary napkin of the present invention has componentswhich may move apart from other components of the sanitary napkin whenthe sanitary napkin is worn. In particular, the sanitary napkin has atopsheet that may be moved away from the absorbent core of the sanitarynapkin to contact and conform with the wearer's body.

The sanitary napkin of the present invention comprises at least fourprimary components. These are a liquid pervious topsheet, a liquidimpervious backsheet, an absorbent core positioned between the topsheetand the backsheet, and a liquid pervious spacing structure for movingthe topsheet away from the core (the "spacing structure"). The spacingstructure is generally positioned between the topsheet and the core.

The spacing structure can be an element of any shape (such as a foldedsheet) that is capable of spacing the topsheet away from the core whenit is subjected to laterally compressive forces. The spacing structurehas an uncompressed configuration, and a compressed configuration. Thespacing structure is in its uncompressed configuration when it is notbeing subjected to any laterally compressive forces, such as thoseapplied by the upper portions of the wearer's thighs when the sanitarynapkin is worn. The spacing structure also has its own longitudinal andtransverse axes. The spacing structure comprises several portions,including an upper portion, a lower portion, and opposed lateral sides.The upper portion of the spacing structure is positioned between thetopsheet and the lower portion. The lower portion is adjacent to corewhen the spacing structure is in its uncompressed configuration. Atleast a section of the lower portion is connected to at least part ofthe core to define an attached section of the lower portion. Therelationship between the upper portion and the lower portion is suchthat parts of the upper portion overlay parts of the lower portion whenthe spacing structure is in its uncompressed configuration. When thespacing structure is compressed from the sides, the opposed lateralsides may move inwardly toward the longitudinal centerline. This resultsin at least some of the upper portion moving the topsheet apart from theabsorbent core.

In one embodiment, the sanitary napkin of the present invention also hasan absorbent core that separates from the backsheet of the sanitarynapkin. The separation of the absorbent core from the backsheet providesincreased protection from soiling of the wearer's undergarments. Thisseparation is made possible by virtue of the fact that the core isjoined to the backsheet along the longitudinal edges of the sanitarynapkin and along at least one transverse juncture. The remainder of thecore is unattached to the backsheet so the unattached portion of thecore may move apart from the backsheet. This embodiment of the sanitarynapkin is also provided with a means for controlling the separation ofthe core from the backsheet.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims particularly pointing outand distinctly claiming the subject matter which is regarded as formingthe present invention, it is believed that the invention will be betterunderstood from the following description which is taken in conjunctionwith the accompanying drawings in which like designations are used todesignate substantially identical elements, and in which:

FIG. 1 is a top plan view of the sanitary napkin of the presentinvention.

FIG. 2 is a section view taken along line 2--2 of FIG. 1 which shows thesanitary napkin of the present invention in its uncompressedconfiguration.

FIG. 3 is a section view taken along line 3--3 of FIG. 1 of the sanitarynapkin in its uncompressed configuration.

FIG. 4 is a sectional view taken from an angle similar to that of FIG. 2which shows the sanitary napkin in a compressed configuration.

FIG. 5 is a sectional view taken from a similar angle to that of FIG. 3which shows the sanitary napkin in a compressed configuration andarticulated to the open position.

FIG. 6 shows an alternative version of the sanitary napkin of thepresent invention in which a pervious material is placed between thetopsheet and the spacing structure.

FIGS. 7, 7A and 8-11 show alternative versions of the spacing structure.

FIGS. 12 and 13 show different types of supports for the spacingstructure.

FIG. 14 is an alternative version of the sanitary napkin of the presentinvention that has a tissue strip positioned in the interior of thespacing structure.

FIG. 15 shows a sanitary napkin having an optional interliner of analternative configuration.

FIG. 16 is a view similar to FIG. 5 showing the sanitary napkin withoutthe optional interliner.

FIGS. 17-20 show alternative means for controlling the separation of thecore of the sanitary napkin from the backsheet.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings, a preferred embodiment of a disposableabsorbent article of the present invention is shown in FIGS. 1-3.

As used herein, the term "absorbent article" refers to articles whichabsorb and contain body exudates. More specifically, the term refers toarticles which are placed against or in proximity to the body of thewearer to absorb and contain the various exudates discharged from thebody. The term "absorbent article" is intended to include sanitarynapkins, pantiliners, and incontinent pads (articles worn in the crotchregion of a garment). The term "disposable" refers to articles which areintended to be discarded after a single use. That is, disposablearticles are not intended to be laundered or otherwise restored orreused). In the preferred embodiment illustrated, the absorbent articleis a sanitary napkin designated 20.

1. Overall Characteristics of the Absorbent Article

The overall characteristics of the sanitary napkin 20 of the presentinvention will be discussed first.

The sanitary napkin 20 has two surfaces, a body surface 20a and agarment surface 20b. The sanitary napkin 20 is shown in FIG. 1 as viewedfrom its body surface 20a. The body surface 20a is intended to be wornadjacent to the body of the wearer. The garment surface 20b of thesanitary napkin 20 (shown in FIG. 2) is on the opposite side and isintended to be placed adjacent to the wearer's undergarments when thesanitary napkin 20 is worn.

The sanitary napkin 20 has two centerlines, a principal longitudinalcenterline l₁ and a principal transverse centerline t_(l). As usedherein the term "longitudinal" refers to a line, axis or direction inthe plane of the sanitary napkin 20 that will be generally aligned with(e.g., approximately parallel to) a vertical plane which bisects astanding wearer into left and right body halves when the sanitary napkin20 is worn. The term "transverse" refers to the line, axis or directiongenerally perpendicular to the longitudinal direction which lies withinthe plane of the sanitary napkin 20. The sanitary napkin 20 has alongitudinal dimension that runs in the general direction of theprincipal longitudinal centerline l₁, and a transverse dimension thatruns in the general direction of the principal transverse centerline t₁.The sanitary napkin 20 is typically longer in the longitudinal dimensionthan in the transverse dimension.

FIG. 1 shows that the sanitary napkin 20 also has two spaced apartlongitudinal edges 22 and two spaced apart transverse or end edges (or"ends") 24, which together form the periphery 26 of the sanitary napkin20. When the sanitary napkin 20 is worn, one of the end edges 24 will beoriented toward the front of the wearer, and one of the end edges 24will be oriented toward the rear of the wearer. The end edge 24 orientedtoward the front of the wearer is designated 24a, and the end edgeoriented toward the rear of the wearer is designated 24b.

The properties of the sanitary napkin 20 include its thickness, surfacearea, and its flexibility. The sanitary napkin 20 can be of anythickness, including relatively thick or relatively thin. The embodimentof the sanitary napkin 20 shown in the drawings is intended to be anexample of a relatively thin sanitary napkin 20. It should beunderstood, however, when viewing the drawings that the number of layersof material shown cause the sanitary napkin 20 to appear much thickerthan it actually is. A "thin" sanitary napkin 20 will generally have acaliper of less than about 10 millimeters. Still, some thin sanitarynapkins have a caliper of less than about 7 millimeters. The abovecalipers are to be measured with a comparator gauge having a test weightof approximately 80.0 grams. The comparator gauge should have acomparator foot that weighs approximately 10 grams and has a diameter ofabout 2.54 centimeters. The comparator gauge should have a contactsurface area of approximately 5.1 square centimeters. The surface areaof the topsheet 28 of the sanitary napkin 20 of the present inventionshould be at least about 100 square centimeters. This will preventdischarged fluids from missing the target that the sanitary napkin 20provides. The sanitary napkin 20 should also be preferably relativelyflexible, so that it is comfortable for the wearer.

FIG. 2 shows the individual components of the sanitary napkin 20. Thesanitary napkin 20 of the present invention generally comprises fourprimary components. These include a liquid pervious topsheet 28, aliquid impervious backsheet (or "barrier means") 30, an absorbent core36, and a liquid pervious spacing structure for moving the topsheet awayfrom the absorbent core (the "spacing structure") 44. The absorbent core36 is positioned between the topsheet 28 and the backsheet 30. Thespacing structure 44 is positioned between the topsheet 28 and theabsorbent core 36 in the embodiment shown in FIG. 2. As shown in FIG. 2,the spacing structure 44 has several portions. These include an upperportion 46, a lower portion 48, and opposed lateral sides 52. Thecomponents of the sanitary napkin 20 and the portions of the spacingstructure 44 are described in greater detail below.

The sanitary napkin 20 of the present invention can also be providedwith any optional additional components that are known in the art. Theoptional components may include one or more wicking layers 58 (such asis shown in FIG. 6), an optional interliner 60 (FIG. 2), side flaps 62(FIGS. 1 and 2), an adhesive fastening means 64 (FIG. 2), and aremovable cover strip or release liner 66 (FIG. 2). In the embodimentshown in FIG. 6, the sanitary napkin 20 of the present invention isprovided with a wicking layer 58 positioned between the topsheet 28 andthe absorbent core 36. As shown in FIG. 2, the optional interliner 60 ispositioned between the absorbent core 36 and the backsheet 30. Thesanitary napkin 20 may be provided with side flaps or "wings" 62 thatare folded around the crotch portion of the wearer's panties. (Thewearer's panties or undergarments are designated U in the drawings.) Theadhesive fastening means 64 serves as a means for attaching the sanitarynapkin 20 to the undergarment of the wearer. The removable release liner66 covers the adhesive fastening means 64 in order to keep the adhesivefrom drying out or sticking to a surface other than the crotch portionof the undergarment prior to use. (These optional components are alsodescribed in greater detail below.)

The key features of the sanitary napkin 20 of the present inventioninclude the fact that the sanitary napkin 20 has certain componentswhich may move apart from other components of the sanitary napkin. Themovement of some components apart from other components of the sanitarynapkin 20 is also referred to as the "decoupling of", or "separationfrom" the other components. In addition, not only may some componentsmove apart, there may be separation of more than one set of componentsin the sanitary napkin 20 of the present invention. This separation ofmultiple components may be referred to as "compound decoupling" forshort. In one embodiment, there is separation of at least two sets ofcomponents of the sanitary napkin 20. The separation of two sets ofcomponents is referred to as "dual" or "double" decoupling for short.

The first set of components that may move apart comprises the topsheet28 and the absorbent core 36. In the case of the first set ofcomponents, when the sanitary napkin 20 is worn, at least a portion ofthe topsheet 28 may be moved apart from the absorbent core 36 by thespacing structure 44. The second set of components comprises theabsorbent core 36 and the backsheet 30. The separation of the second setof components is optional. The separation of the components provides thesanitary napkin 20 with improved contact with the wearer's body andincreased protection from soiling of the wearer's undergarments.

Several matters should be understood with reference to the decoupling ofthe components of the sanitary napkin 20.

The separation or decoupling of the components refers to a movement ofone component apart from another in a direction generally perpendicularto the principal longitudinal and transverse axes of the sanitary napkin(that is, in the "Z-direction"). The "Z-direction" is an orientationwith respect to the sanitary napkin 20 of the present invention if thesanitary napkin 20 is placed in a Cartesian coordinate system in itsflat, laid out condition of FIG. 1 so that the garment side 20b of thesanitary napkin 20 lies in the plane formed by the x and y axes. Theprincipal longitudinal and transverse centerlines l₁ and t₁ of thesanitary napkin 20 lie in the plane formed by the x and y axes. The"Z-direction" is the direction that is perpendicular to the plane ofeither surface of the sanitary napkin 20 when it is in such a flat, laidout configuration.

The second matter relates to the nature of the separation of thecomponents. Typically, as used herein, the moving of the componentsapart, or the "decoupling" of the components refers to a situation inwhich portions of the components are joined or attached (and theremaining portions are unattached) before, during and after decoupling.The unattached portions move apart during the decoupling, while theattached portions remain joined together. The moving of the componentsapart may alternatively refer to a situation in which the attachedportions of the components partially or completely separate with theunattached portions. Both types of decoupling are intended to be withinthe scope of the present invention.

A third matter relates to when separation occurs, and to the amount ofseparation. The components of the sanitary napkin 20 need only becapable of separation. The present invention is, thus, not limited tosanitary napkins having components that will separate in all cases andunder all conditions. There may be certain circumstances in which thecomponents of the sanitary napkin 20 will remain in contact with eachother. The components must only separate enough for the sanitary napkin20 to be operable. Preferably, the components that are capable ofseparating will in fact separate when the sanitary napkin 20 is worn.

In the following sections of this description, the characteristics ofthe components of the sanitary napkin 20 are discussed in greater detail(Section 2). The separation of the topsheet 28 from the absorbent core36 is discussed in Section 3 in conjunction with the spacing structure44. The optional components are discussed in Section 4. The separationof the absorbent core 36 from the backsheet 30 is discussed in Section5. In addition to the description provided below, it should also beunderstood that the sanitary napkin 20 of the present invention could beconstructed in accordance with U.S. Pat. No. 4,950,264, issued to Osbornon Aug. 21, 1990, previously incorporated by reference herein. However,in such a case, the sanitary napkin described in the Osborn patent mustbe provided with the decoupling features of the present invention.

2. The Individual Components of the Absorbent Article

Looking at the components of the sanitary napkin 20 more specifically,FIG. 2 shows the liquid pervious topsheet (or simply the "topsheet") 28overlies, and is folded around several of the other components of thesanitary napkin 20. The topsheet 28 is oriented towards and contacts thebody of the wearer. The topsheet 28 is the portion of the sanitarynapkin 20 that initially receives bodily discharges. The topsheet 28 hasa body-facing side (or "body surface") 28a and a core-facing side 28b.The body-facing side 28a of the topsheet 28 generally forms at least aportion of the body surface 20a of the sanitary napkin 20. FIG. 1 showsthat the topsheet 28 has two longitudinal edges 28c and two end edges28d.

The topsheet 28 should permit liquids to readily transfer through itsthickness toward the absorbent core 36. The topsheet 28 should,therefore, be liquid pervious. The topsheet 28 should also be flexibleand nonirritating to the wearer's skin. As used herein the term"flexible" refers to materials which are compliant and readily conformto the shape of the body or respond by easily deforming in the presenceof external forces. Preferably the topsheet 28 is not noisy, to providediscretion for the wearer. The topsheet 28 should be clean in appearanceand somewhat opaque to hide the bodily discharges collected in andabsorbed by the core 36. The topsheet 28 should further exhibit goodstrikethrough and a reduced tendency to rewet, permitting bodilydischarges to rapidly penetrate the topsheet 28 to the core 36, but notallowing such discharges to flow back through the topsheet 28 to theskin of the wearer.

The topsheet 28 preferably also has a plurality of apertures to permitliquids deposited thereon to pass through to the core 36. Such aperturesmay, but need not, also be present in any extension of the topsheet 28that may comprise a portion of the flaps 62. If apertured, the topsheet28 should have about 5 to about 60 percent open area, preferably, about25 percent, and a thickness of about 0.01 to about 0.05 millimeters. Ifdesired, the topsheet 28 may be sprayed with a surfactant to enhancefluid penetration to the core 36. The surfactant should typically benonionic and should be nonirritating to the skin. A surfactant densityof about 0.01 milligrams per square centimeter of topsheet 28 area issuitable. A suitable surfactant is sold by the Glyco Chemical, Inc. ofGreenwich, Conn., as Pegosperse 200 ML. The topsheet 28 may also haveabsorbent capacity if the core 36 has a capillary system or aZ-direction system of fibers.

A suitable topsheet 28 may be made from a number of different materials,such as nonwoven materials and perforated polyolefinic films. Thetopsheet 28 may be manufactured by any suitable process. A particularlysuitable topsheet 28 may be made in accordance with U.S. Pat. No.4,342,314 issued Aug. 3, 1982 to Radel et al. and U.S. Pat. No.4,463,045 issued Jul. 31, 1984 to Ahr et al., which patents areincorporated herein by reference. An elastically inextensible topsheet28 made of model X-3265 or model P1552 apertured formed film sold by theEthyl Corporation, Visqueen Division, of Terre Haute, Ind. has also beenfound to work well in sanitary napkins.

The backsheet 30 is shown in FIG. 2. The backsheet 30 is the componentof the sanitary napkin 20 that prevents the exudates from wettingarticles which contact the sanitary napkin 20. Typically, the articleswhich come in contact with the sanitary napkin 20 would be the wearer'spanties. The present invention is also concerned, however, with keepingthe wearer's body and clothing free from soiling.

As shown in FIG. 2, the backsheet 30 has a core-facing side 30a and agarment side 30b. At least a portion of the core-facing side 30a of thebacksheet 30 will ordinarily face the core 36. It is also within thescope of the present invention for portions of the core-facing side 30aof the backsheet 30 (such as wings 62) to be folded so that they may notnecessarily always face the core 36. However, the core-facing side 30aof the backsheet 30 can be distinguished from the garment side 30b ofthe backsheet 30 because the core-facing side 30a is the side of thebacksheet 30 that is joined to the topsheet 28 and core 36. The garmentside 30b of the backsheet 30 generally forms the garment surface 20b ofthe sanitary napkin 20. FIG. 1 shows that the backsheet 30 has twolongitudinal edges 30c and two end edges 30d.

The backsheet 30 may be any flexible, liquid impervious material thatprevents discharges collected by the sanitary napkin 20, (particularlydischarges which may not be completely absorbed by the core 36), fromescaping the sanitary napkin 20 and soiling the undergarments andclothing of the wearer. Preferably, the backsheet 30 is not noisy, toprovide discretion for the wearer. The backsheet 30 may also beimpervious to malodorous gases generated by bodily discharges, so thatthe malodors do not escape and become noticed by the wearer and others.

As shown in FIG. 2, the backsheet 30 is preferably comprised of twolayers. In the embodiment shown in FIG. 2, the backsheet 30 may comprisea first layer 32 of lofted material disposed on the core-facing side 30aof the backsheet 30. The purpose of the first layer 32 is to provide acomfortable, non-irritating surface against the body of the wearer. Thelofted layer may be comprised of any suitable material, such as anonwoven material. Preferably, the lofted layer comprises a hydrophobicnonwoven material. The second layer 34 may be disposed on the garmentside 30b of the backsheet 30, and may comprise a fluid impervious film.A low density polyethylene material about 0.01 to about 0.05 millimetersin thickness, preferably about 0.02 millimeters in thickness, has beenfound to work well as this second layer 34. A polyethylene film, such asis sold by the Ethyl Corporation, Visqueen Division, under modelXP-39385 has been found particularly well suited for this second layer.The backsheet 30 may also be made of a soft, cloth-like material whichis hydrophobic relative to the topsheet 28. A polyester or polyolefinicfiber backsheet 30 has been found to work well. A particularly preferredsoft, cloth-like backsheet 30 material is a laminate of a polyesternonwoven material and a film such as described in U.S. Pat. No.4,476,180 issued to Wnuk on Oct. 9, 1984, which is hereby incorporatedby reference herein.

FIG. 2 shows the attachment of the backsheet 30 and topsheet 28. Thetopsheet 28 is joined to the core-facing side 30a of the backsheet 30along the longitudinal edges 28c of the topsheet 28. The topsheet 28 andbacksheet 30 are also joined along at least one transverse line, whichpreferably coincides with the end edge 24a oriented toward the front ofthe wearer when the sanitary. napkin 20 is worn. The topsheet 28 andbacksheet 30 are, preferably, unattached to each other at the end edge24b oriented toward the rear of the wearer.

The characteristics of the absorbent core 36 are also shown in FIG. 2.The absorbent core (or simply "the core") 36 serves as a means ofabsorbing bodily fluids. In particular, the absorbent core 36 is themeans for collecting and containing bodily discharges, particularlymenses, deposited thereon or which otherwise traverse through the liquidpermeable topsheet 28. The absorbent core 36 has a body-facing side (or"first major surface") 36a and a garment-facing side (or "second majorsurface") 36b. FIG. 1 shows that the absorbent core 36 has twolongitudinal edges 36c and two end edges 36d.

The core 36 need not have a total absorbent capacity much greater thanthe total amount of bodily discharges to be absorbed. In the embodimentshown in FIG. 2, the core 36 is preferably narrow and thin, so it iscomfortable to the wearer. For the embodiment described herein thecapacity of the core 36 should be at least about 2 grams of 0.9 percentsaline solution. Suitable saline solution is sold by TravenolLaboratories of Deerfield, Ill. The core 36 should also be conformableand nonirritating to the skin. The core 36 should be sized to registerwith the topsheet 28 and backsheet 30. The core 36 is preferablypositioned between the topsheet 28 and backsheet 30. The position of thecore 36 prevents the absorbent material of the core 36 from shredding orbecoming detached while the sanitary napkin 20 is worn. The position ofthe core 36 also ensures proper containment of bodily discharges. Thecore 36 may be of any suitable shape. Preferably, the core 36 is eitherrectangular or hourglass-shaped.

The absorbent core 36 can be made of a number of different types ofmaterials. Suitable core 36 materials include combinations of airfelt,such as cellulose wadding and fibrated communition pulp; layers oftissue paper; and absorbent gelling materials. A suitable tissue papercore can be made in accordance with U.S. Pat. No. 4,191,609 issued Mar.4, 1980 to Trokhan, which is hereby incorporated by reference herein. Ifabsorbent gelling materials are used in the core 36, particularlypreferred absorbent gelling materials are those made in accordance withU.S. Pat. No. 4,654,039 issued Mar. 31, 1987 to Brandt, et al. which ishereby also incorporated by reference herein.

Preferably, the core 36 comprises a laminate of absorbent gellingmaterials and tissue. A suitable laminate of absorbent gelling materialsand tissue may be purchased from the Grain Processing Corporation ofMuscatine, Iowa, under Model Number L535. A particularly preferred andillustrated core 36 has two layers of tissue with absorbent gellingmaterials 42 disposed between the layers. The two layers can be formedfrom a single sheet of tissue that is folded over on itself as shown inFIG. 2. Alternatively, the two layers can be provided by separate sheetsof tissue. In the latter case, the two layers can either be made of thesame material, or of different materials. For example, the upper half ofthe core, that is, the layer 38 that is closer to the topsheet 28, canbe made of a wet laid tissue having a wet tensile strength of about 15grams per centimeter of width. The lower half of the core, that is, thelayer 40 closer to the backsheet 30, can be made of an air laid tissuecontaining about 0,005 grams per square centimeter absorbent gellingmaterials. This dual layered core 36 arrangement provides the advantagethat the tissue layers prevent contact of the absorbent gelling materialwith the body of the wearer.

3. The Spacing Structure for Separating the First Set of Components

The first set of components capable of separation comprises the topsheet28 and the absorbent core 36.

The liquid pervious spacing structure 44 for moving (or "spacing") thetopsheet away from the absorbent core is shown in FIG. 2. The liquidpervious spacing structure 44 may also be referred to herein by anyabbreviated version of its name, including, but not limited to "thespacing structure". (Alternatively, the spacing structure 44 may bereferred to by a name that describes its characteristics, such as the"compressible structure" or the "deformable structure"). As its namesuggests, the spacing structure 44 facilitates the separation of thefirst set of components.

The purpose of the spacing structure 44 is to provide the sanitarynapkin 20, particularly the topsheet 28, with improved contact with thewearer's body. The spacing structure 44 advantageously utilizes thecompressive forces exerted by the upper portions of the wearer's thighs.(The "upper portions" of the wearer's thighs include, but are notlimited to those portions of the thighs that are in direct contact withthe sanitary napkin 20 when the sanitary napkin is worn.) While notwishing to be bound by any particular theory, it is believed that whenthe sanitary napkin 20 is subjected to the compressive forces of thethighs of the wearer, the shape of the spacing structure 44 will bedeformed so that at least a portion of the upper portion 46 of thespacing structure 44 assumes a convex upward configuration. A "convexupward" configuration is one that is vaulted or arched so that the topof the arch is upward (i.e., adjacent the topsheet 28), and the bases ofthe arch are adjacent the core 36. The compressive forces cause parts ofthe spacing structure 44, along with at least a portion of the topsheet28 that is disposed above the spacing structure 44, to move apart fromthe absorbent core 36 toward the wearer's vaginal introitus.

As shown in FIG. 2, the spacing structure 44 is positioned between thetopsheet 28 and the absorbent core 36. The spacing structure 44 can alsobe positioned in other places. For instance, as shown in FIG. 6, thespacing structure 44 could be positioned between the optional wickinglayer 58 and the core 36. In such an embodiment, wicking layer 58 can beprovided with absorptive capacity and can serve an absorptive function.When this is the case, the wicking layer 58 may be considered to be apart of the absorbent core 36. Therefore, in the embodiment shown inFIG. 6, the spacing structure 44 may be considered to be positionedwithin the absorbent core 36, or possibly even a part of the core 36.

The spacing structure 44 (and the sanitary napkin 20 in general) has anuncompressed configuration and a compressed configuration. The sanitarynapkin 20 and the spacing structure 44 are shown in an uncompressedconfiguration in FIG. 2, and in a compressed configuration in FIG. 4. Asused herein, the term "uncompressed" refers to the conditions that thesanitary napkin 20 and the spacing structure 44 are under before anycompressive forces, particularly any laterally compressive forces areapplied to the sanitary napkin 20. The term "compressed" refers to theconditions that the sanitary napkin 20 and the spacing structure 44 areunder when such laterally compressive forces are applied. The term"laterally compressive forces" refers to forces applied (from thelongitudinal edges 22) inward in the transverse direction toward thecenter of the sanitary napkin 20 (shown by arrows F in FIG. 4). Sincethe mere act of putting the sanitary napkin 20 on will likely subject itto some laterally compressive forces, the sanitary napkin 20 may only bein an uncompressed configuration before it is put on by the wearer.

The overall characteristics of the spacing structure 44 are shown inFIGS. 1 and 2. As shown in FIG. 1, the spacing structure 44 has its ownlongitudinal centerline 12 and transverse centerline t₂. Thelongitudinal and transverse centerlines of the spacing structure 44 areuseful to describe, among other things, the position and orientation ofthe spacing structure 44 under the surface of the topsheet 28. Thespacing structure 44 may be positioned in various locations under thesurface of the topsheet 28. For instance, the spacing structure 44 maybe centered relative to the other components of the sanitary napkin 20so that the longitudinal and transverse centerlines of the spacingstructure l₂ and t₂, coincide with the principal longitudinal andtransverse centerlines 1₁ and l₂ of the sanitary napkin 20.Alternatively, the spacing structure 44 may positioned so that it is notcentered on the sanitary napkin 20 and the centerlines of the spacingstructure 44 are offset from either of the principal centerlines of thesanitary napkin 20. In the embodiment shown in FIG. 1, the spacingstructure 44 is centered relative to the centerlines of the sanitarynapkin 20.

The spacing structure 44 can also be either symmetrical or asymmetricalabout the principal longitudinal and transverse centerlines, l₁ and t₁,and about its own longitudinal and transverse centerlines l₂ and t₂. Inthe embodiment shown in FIGS. 1 and 2, the spacing structure 44 issymmetrical about both its own longitudinal and transverse centerlinesl₂ and t₂ and about the principal longitudinal and transversecenterlines l₁ and t₁.

The spacing structure 44 can be an element of any shape provided it iscapable of spacing the topsheet 28 away from the core 36 when it issubjected to the laterally compressive forces described above. Theoverall spacing structure 44 should, therefore, be laterallycompressible. As used herein, the term "laterally compressible" meansthat portions of the spacing structure 44 will move inward (rather thantend to spring back) when the spacing structure 44 is subjected tolaterally compressive forces. The spacing structure 44 should also bedeformable in the sense that when the sides 52 of the spacing structure44 are moved inward, at least part of the top of the spacing structure44 will "pop up". The spacing structure 44 may be compressible becauseit is comprised of one or more pieces of a material that is inherentlycompressible. Preferably, however, the material comprising the spacingstructure 44 is ordinarily not inherently compressible, but is arrangedinto a form or configuration, by folding or otherwise, that renders itlaterally compressible.

In one preferred embodiment shown in FIG. 2, the spacing structure 44 isin the form of a folded sheet of material. The sheet of material has twosides. In the embodiment shown in FIG. 2, one side, body-facing side44a, faces the body of the wearer when the sanitary napkin 20 is wornand the other side, garment-facing side 44b, faces the wearer'sundergarments. The sheet of material has a longitudinal dimension and atransverse dimension. Generally, the longitudinal dimension of the sheetwill be greater than the transverse dimension, but the oppositerelationship is possible. The sheet typically has two longitudinaledges, designated 44c, that generally run in the longitudinal directionwhen the sheet is placed in the sanitary napkin 20. The portions of thesheet located adjacent the longitudinal edges are the "longitudinal edgeportions" 44c'. The sheet of material will also usually have twotransverse edges or ends 44d (which in the embodiment shown in FIGS. 1and 2, also form the transverse edges or ends of the spacing structure44).

The sheet of material is generally folded about at least one (imaginary)axis that runs in the longitudinal direction. The sheet of material mayhave identifiable fold lines or creases, but such fold lines are notessential. If the sheet is arranged in the form of a tube, for instance,it will not have any identifiable fold lines. If the sheet of materialhas identifiable fold lines, they will also generally be oriented in thelongitudinal direction. The sheet can be folded about any number ofaxes, from one to a virtually infinite number. In the preferredembodiment shown in FIG. 2, the sheet is folded in two places. The folds44e are located in the longitudinal edge portions 44c' of the sheet nearthe longitudinal edges 44f of the spacing structure 44. The folds 44egive the folded sheet a "spring-like" property.

The sheet of material can be folded in many different ways. Suitablefolded configurations include configurations in which the longitudinaledge portions 44c' of the sheet are folded to either overlie or bedisposed under one side of the sheet. Other suitable configurationsinclude configurations in which the longitudinal edge portions 44c' ofthe sheet are folded to overlie opposite sides of the sheet, such aswhen the sheet is folded into a z-folded configuration. In theembodiment shown in FIG. 2, the longitudinal edge portions 44c' arefolded under one side of the sheet, the garment-facing side 44b of thesheet. The sheet is folded so the folds 44e are located along thelongitudinal edges of the folded sheet of material (which, in this caseare the same as the longitudinal edges 44f of the spacing structure 44).In other words, the folds 44e are on the lateral sides 52 of the spacingstructure 44. The sheet may be folded so that the longitudinal edges 44care spaced apart (shown in FIGS. 2 and 4), meet (FIG. 7), or overlap(FIG. 8).

The spacing structure 44 could be in the form of a tube (as shown inFIG. 12), or (as in FIG. 9) in the form a roll of more than onerevolution. In addition, such a tube or roll can be flattened (as shownin FIGS. 7 and 9, respectively). As used herein, the term "flattened"means compressed in the Z-direction. The transverse cross-sectionalshape of different embodiments of the spacing structure 44 can vary. Forinstance, the cross-section can be flattened so it appears as twolayers, or it can be round, oval, elliptical, polygonally-shaped (FIG.10), or C-shaped prior to its deformation. The shape of spacingstructure 44 should be such that it does not have any sharp corners,edges, or fold lines (at least on its upper portion 46) that wouldirritate the wearer. Preferably, as shown in FIG. 2, the spacingstructure 44 is a C-shaped (or C-folded) piece of material. In theembodiment shown in FIG. 2, the piece of material is oriented so thatthe opening of the letter "C" formed by the folding is facing theabsorbent core 36.

A variation of the C-folded spacing structure 44 is shown in FIG. 7A. Inthe embodiment shown in FIG. 7A, the C-folded material is oriented sothat the opening of the C-fold is facing the topsheet 28. For thespacing structure 44 shown in FIG. 7A to work properly, the upperportion 46 of the spacing structure 44 should be secured to thecomponent (such as topsheet 28) that is positioned immediately above.

The spacing structure 44 could alternatively be in any other suitablefolded configuration, including the modified C-folded configurationshown in FIG. 11. The spacing structure 44 shown in FIG. 11 is a sheetof material with two sets of longitudinal folds 44e' and 44e", one ofwhich is disposed above the other, and longitudinal edges 44c whichextend outward from the longitudinal centerline 1₂ toward the(longitudinal) edges 36c of the absorbent core 36. The first pair oflongitudinal folds 44e' comprises one fold on each side of thelongitudinal centerline l₂ of the spacing structure 44. The first pairof folds 44e' occur where the sheet has been folded inward under thegarment-facing side 44b of the sheet. The second pair of folds 44e"comprises two opposed folds where the sheet has been folded in oppositedirections outward under the garment-facing side 44b of the sheet. Inthe embodiment shown in FIG. 11, one fold of the second pair of folds44e" is on each side of the longitudinal centerline l₂ of the spacingstructure 44. In other embodiments, these folds can be closer togetherso they meet at the longitudinal centerline l₂. As shown in FIG. 11, thesecond pair of folds 44e" are positioned inboard (i.e., closer to thelongitudinal centerline l₂) than the first pair of folds 44e. In theembodiment shown in FIG. 11, the longitudinal edges 44c of the foldedsheet extend outward away from the principal longitudinal centerline l₁approximately the same distance as the longitudinal edges 36c of theabsorbent core 36. In other embodiments, the longitudinal edges 44c mayonly extend part of the distance to the longitudinal edges 36c of thecore 36.

As shown in FIG. 1, the spacing structure 44 has a longitudinaldimension and a transverse dimension. (As shown in FIG. 2, thesedimensions of the spacing structure 44 will generally be different fromthe longitudinal and transverse dimensions of the sheet before it isfolded.) The longitudinal dimension of the spacing structure 44 shouldbe greater than the transverse dimension so that the spacing structure44 will be able to conform a portion of the body surface 20a of thesanitary napkin 20 to the space between the wearer's labial tissue. Thespacing structure 44 can extend from between about 5% to about 100% ofthe length of the absorbent core 36. The absolute length of the spacingstructure 44 may, thus, be between about 0.75 inches (about 2 cm.) andabout 12.5 inches (about 32 cm.), preferably, about 14 cm. Preferably,the spacing structure 44 will extend approximately 70% of the length ofthe absorbent core 36. The width of the spacing structure 44 shouldextend between about 20% to about 80% of the width of the core 36,preferably between about 30% to about 70%, so the spacing structure 44will be compressed when the sanitary napkin 20 is subjected to lateralcompressive forces, yet will still be narrow enough so that it canconform to the wearer's anatomy. The absolute width of the spacingstructure 44 may, thus, be between about 2 cm. and about 6 cm.Preferably, the width of the spacing structure 44 is about 1.5 inches(about 4 cm).

The plan view shape of the spacing structure 44 (that is, the shape ofthe spacing structure 44 when viewed from directly above) when thesanitary napkin 20 is in its flat, laid out condition of FIG. 1, canalso vary. For instance, the plan view shape of the spacing structure 44can be rectangular, oval, or some other suitable shape. In theembodiment shown in FIG. 1, the plan view shape of the spacing structure44 is rectangular.

The spacing structure 44 comprises an upper portion 46, a lower portion48, and opposed lateral sides (or "sides") 52. It should be understoodthat the designation of certain portions of the spacing structure 44 asan upper portion, a lower portion, and lateral sides is primarily forconvenience of description, rather than to specify that one portion ofthe spacing structure 44 is necessarily a separate element or iscomprised of a separate piece of material. The division of the spacingstructure 44 into portions is used to describe the overall configurationof the spacing structure 44. The division of the spacing structure 44into portions is also used to describe the shape of the spacingstructure 44 before and after it has been subjected to laterallycompressive forces. The different portions of the spacing structure 44are also useful in describing the general way the spacing structure 44moves in response to compressive forces.

The portions of the spacing structure 44 may all be comprised of thesame piece of material (i.e., the spacing structure 44 may be unitary).Alternatively, the portions of the spacing structure 44 may be comprisedof one or more separate pieces of material. Preferably, as shown in thepreferred embodiment of the present invention of FIG. 2, the spacingstructure 44 is unitary. In addition, as shown in FIG. 2, the beginningand end of some portions of the spacing structure 44 may often not bemarked by a precise line of demarcation. This is particularly true inthe case of the opposed lateral sides 52 of the spacing structure 44. Asshown in FIG. 2, for instance, it may not necessarily be easy to tellwhere the lateral sides 52 of the spacing structure 44 end and the upperportion 46 begins. The lack of precise boundries between the differentportions of the spacing structure 44 is not critical, however, since thedivision of the spacing structure 44 into portions is primarily forconvenience of description. The different portions of the spacingstructure 44 are sufficiently defined below so that one should be ableto tell whether a given spacing structure has an upper portion, a lowerportion, and opposed lateral sides.

The upper portion 46 of the spacing structure 44 is shown in FIG. 2. The"upper portion" overlies other parts of the spacing structure when thespacing structure 44 is in its uncompressed configuration. As usedherein, the term "overlies" refers to the relationship in which aportion of the sanitary napkin 20 is disposed over another portion inthe Z-direction when the sanitary napkin 20 is in its flat, laid outconfiguration of FIG. 1. A sanitary napkin will be considered to have aspacing structure with an "upper portion" within the meaning of thatterm as used herein, if any parts of the spacing structure in issueoverlay other parts of the spacing structure.

The upper portion 46 is positioned between the topsheet 28 and the lowerportion 48. In the embodiment shown in FIG. 2, when there is no otherlayer positioned between the upper portion 46 and the topsheet 28, theupper portion 46 is adjacent at least a portion of the (core-facing side28b of the) topsheet 28.

At least some of the upper portion 46 contacts the component that liesimmediately above it to form a contact area 54. The term "contact area"refers to the area on the surface of the spacing structure 44 that is incontact with the component above. The upper portion 46 need only be incontact with the component that lies above it at some stage when thespacing structure 44 is being compressed (when the spacing structure 44moves from an uncompressed configuration to a compressed configuration).The forces exerted on the contact area 54 cause the topsheet 28 to moveapart from the absorbent core 36. In the embodiment shown in FIG. 2, thecomponent immediately above the spacing structure 44 is the topsheet 28.Alternatively, the component positioned above the upper portion 46 couldbe a pervious or absorbent component of some type that is positionedbetween the upper portion 46 and the topsheet 28. For ease ofdescription, the upper portion 46 will usually be described throughoutthis discussion as being in contact the topsheet 28. It should beunderstood, however, that the description will apply equally well to thesituation in which the upper portion 46 is in contact with such an othercomponent.

The upper portion 46 of the spacing structure 44 can be secured to thetopsheet 28. More specifically, the upper portion 46 may be secured tothe core-facing side 28b of the topsheet 28. In alternative embodiments,however, the spacing structure 44 may be unsecured to the topsheet 28.In the embodiment shown in FIG. 2, the spacing structure 44 is securedto the topsheet 28 by topsheet securement means 74. In FIG. 2, thetopsheet securement means 74 is an adhesive.

The topsheet securement means 74 can extend over any portion of thetotal surface area of the topsheet 28 between the longitudinal andtransverse edges, 28c and 28d, of the topsheet 28. The topsheetsecurement means 74 may, thus, as shown in FIGS. 2 and 3, coincide inarea with all of the surface area of the upper portion 46.Alternatively, the topsheet securement means 74 may coincide with onlypart of the surface area of the upper portion 46.

The topsheet securement means 74 may also extend outwardly beyond thetransverse and longitudinal edges 44d and 44f of the spacing structure44. Any portions of the topsheet securement means 74 that extend beyondthe edges of the spacing structure 44 will serve to secure thecore-facing side 28b of the topsheet 28 to the absorbent core 36.Preferably, the topsheet securement means 74 is adjacent or inboard ofat least the ends 44d of the spacing structure 44. The topsheetsecurement means 74 could, however, be inboard of one end 44d andoutboard of the other. Preferably, the topsheet securement means 74 isat least inboard of the end 44d' of the spacing structure 44 located tothe rear of the wearer when the sanitary napkin 20 is worn.

The topsheet securement means 74 should not inhibit flow of menses andother exudates to the core 36. If the topsheet securement means 74 is anadhesive, the path of flow to the core 36 can be preserved in severalways, including by spreading the adhesive sufficiently thin so that aplurality of the apertures in the topsheet material are not covered withadhesive. Alternatively, the adhesive could be soluble so that isdissolves when contacted by bodily fluids. Many types of adhesives aresuitable for use as the topsheet securement means 74, includingwater-based adhesives and hot melt adhesives.

As shown in FIG. 2, (at least a portion of) the lower portion 48 of thespacing structure 44 is adjacent the core 36 of the sanitary napkin 20when the spacing structure 44 is in its uncompressed configuration. Thelower portion 48 lies under other parts of the spacing structure 44 whenthe spacing structure 44 is in its uncompressed configuration. As usedherein, the term "under" refers to the relationship in which a portionof the sanitary napkin 20 is disposed below another portion in theZ-direction when the sanitary napkin 20 is in its flat, laid outconfiguration of FIG. 1. A sanitary napkin will be considered to have aspacing structure with a "lower portion" within the meaning of that termas used herein, if any parts of the spacing structure are positionedbelow other parts of the spacing structure.

In the embodiment shown in FIG. 2, part of the spacing structure 44forms at least one support 50 for the rest of the spacing structure 44.The term "support" is used herein to refer to the "legs" that thespacing structure 44 stands on when it rises up to its compressedconfiguration. The supports 50 may, thus, be thought of as being for theupper portion 46 of the spacing structure 44. The supports 50 may becomprised of all or parts of the lower portion 48. The supports 50 may,in addition, or alternatively, also be comprised of all or parts of theopposed lateral sides 52. As shown in FIG. 2, the portions of thespacing structure 44 that comprise the supports 50 depend in part on theway the spacing structure 44 is secured to the absorbent core 36. If theentire lower portion 48 of the spacing structure 44 is secured to thecore, the supports 50 will be at least partially comprised of thelateral sides 52 since the lower portion 48 will not stand up.

Typically, as shown in FIG. 2, there will be at least two supports 50,one on each side of the longitudinal centerline l₂ of the spacingstructure 44. The supports 50 are preferably also on each side of theprincipal longitudinal centerline l₁ of the sanitary napkin 20. Eachsupport 50 comprises at least parts of the longitudinal edge portions44c' of the folded sheet. In FIG. 2, these individual supports 50 aredesignated 50a and 50b. FIG. 12 shows an example of a situation in whichthe spacing structure 44 may be considered to have only one support 50.An example of a situation in which there may be more than two supports50 is shown in FIG. 13. Such a situation could occur when thelongitudinal edge portions 44c' are comprised of discontinuous segmentsof material. Thus, if as shown in FIG. 13, there are five such segmentson each side of the spacing structure 44, there would be a total of tensupports 50.

In several of the embodiments described herein, at least a section ofthe lower portion is connected to at least part of the core 36 to definean attached section 48a of the lower portion 48. Generally, at least oneof the supports 50 may be connected to the core 36. Although bothsupports 50 are connected to the core 36 in the embodiment shown in FIG.2, in alternative embodiments, only one support 50 could be connected tothe core 36. In still other alternative embodiments (such as that shownin FIG. 11), the spacing structure 44 may be unconnected to, but incontact with the core 36. An example of an embodiment in which onesupport 50 is connected to the core 36 occurs if sheet comprising thespacing structure 44 is folded over on itself in an e-foldedconfiguration. In such a case, one support may be connected to the core36, and the other may be connected to part of the spacing structure 44,rather than to the core 36.

The supports 50 (or at least a portion of the supports 50) may, in somecases, be thought of as being pivotally connected to the core 36. Theconnection between the supports 50 and the core 36 resembles a pivotperhaps most when the material that comprises the spacing structure 44is relatively stiff. If the supports 50 are described as being"pivotally connected" to the core 36, it is meant that there is an axisabout which (at least portions of) the supports 50 may turn. Preferably,the axis is oriented in the longitudinal direction. It should beunderstood that it is not necessary that the supports 50 be able torotate a full 360° around this axis, however. As shown in FIGS. 2 and 4,it is only necessary that the supports 50 rotate sufficiently to allowthe spacing structure 44 to rise up from its uncompressed configurationto its compressed configuration when the sanitary napkin 20 iscompressed. It is also not necessary that there be a shaft or pin aboutwhich the supports 50 turn as is sometimes thought of in the case of apivotal connection. Typically, the function normally served by a pinwill be supplied by the means (such as one or more lines of adhesive)used to secure the supports 50 to the core 36.

The supports 50 can be affixed to the core 36 in many different ways.The primary requirements of the manner of affixing the supports 50 tothe core 36 is that the means used to do so be sufficient to allow thespacing structure 44 to pop up when the sanitary napkin 20 iscompressed, and that the manner be stable enough so that the spacingstructure 44 does not get pushed over to one side when compressiveforces are applied. The means used, ("securement means" 76), willtypically be an adhesive, or some other suitable means. There should beat least one region where the supports 50 are secured to the core 36.Preferably, the means used to secure the supports 50 to the core 36 isoriented in a generally longitudinal direction. Such an orientationallows the spacing structure 44 to align with the space between thewearer's labial tissue when the sanitary napkin 20 is worn. If only asingle region of securement is used, it should be disposed near thelongitudinal centerline 12 of the spacing structure 44. In theembodiment shown in FIG. 4, there are at least two spaced apartsecurement means 76 that are disposed on opposite sides of thelongitudinal centerline l₂ of the spacing structure 44. In certaininstances, the spaced apart securement means 76 may be preferred becausesuch a construction will make it easier for the spacing structure 44 topop up and will stabilize the spacing structure 44 by reducing thechance that it could be pushed over to one side.

In the embodiment shown in FIGS. 2 and 4 that has two spaced apartsecurement means 76, the configuration of the securement means 76 canvary. It is preferable, however, that such spaced apart securement means76 are generally longitudinally oriented. They, or parts of them couldbe oriented at an angle to the longitudinal centerline l₂ so long asthey are generally longitudinally oriented. In the embodiment shown, theprincipal longitudinal centerline l₁ of the sanitary napkin 20 coincideswith the longitudinal centerline l₂ of the spacing structure 44, and thesecurement means 76 are parallel to and spaced equidistant from thelongitudinal centerline l₁ of the sanitary napkin 20.

The width of each of the securement means 76 and the distances that theinside and outside edges of the securement means 76 are spaced from theprincipal longitudinal centerline l₁ can vary in different embodiments.Preferably, the widths of each individual region (e.g., line, strip, orother pattern) of adhesive that comprises the securement means 76, andthe total width of the securement means 76 is less than or equal to thewidth of the lower portion 48 of the spacing structure 44. In onepreferred embodiment where there are two spaced apart regions ofadhesive, each of the regions of adhesive is approximately 0.25 inches(0.64 cm.) wide, and are on opposite sides of the principal longitudinalcenterline l₁ and spaced approximately 6 mm. apart between their insideedges. In this embodiment the length of the securement means 76 extendsthe full length of the spacing structure 44.

The adhesive may be applied in any suitable spray pattern, such asspiral, or in longitudinally oriented beads. In addition, the securementmeans 76 could be continuous or intermittent. Preferably, however, thesecurement means are continuous or nearly continuous. In addition, theupper portion 46 of the spacing structure 44 is preferably unsecured toany component lying below between its longitudinal edges 44f so that thespacing structure 44 will be able to stand up when compressed.

The lateral sides 52 in the spacing structure 44 shown in FIG. 2comprise at least the two folded edges of the folded sheet of material.An absorbent article will be considered to have a spacing structure with"opposed lateral sides" as that term is used herein, if its spacingstructure has any portions which are capable of moving inward towardeach other when the spacing structure is compressed from the sides.Typically, when a reference is made to "compressing" the spacingstructure 44, this means that the spacing structure 44 is subjected tocompressive forces that are being applied to the sanitary napkin 20 as awhole, rather than to just the spacing structure 44. In other words, thespacing structure 44 is typically compressed indirectly by the forcesthat are transmitted through the other components of the sanitary napkin20.

The spacing structure 44 is flexible in that when the spacing structure44 is compressed from the sides, the sides 52 may move inwardly towardthe longitudinal centerline l₂. This results in at least some of thecontact area 54 of the upper portion 46 moving the topsheet 28 apartfrom the absorbent core 36 in a direction generally perpendicular to theprincipal longitudinal and transverse centerlines of the sanitary napkin20 (i.e., in the Z-direction). The shape of the spacing structure 44should render the spacing structure 44 resilient enough that it willdeform into the desired shape, but will not have a tendency to return toits uncompressed configuration unless the laterally compressive forcesare removed. The spacing structure 44 should preferably deform when itis subjected to the forces associated with wearing a sanitary napkin.The amount of force exerted on a sanitary napkin depends on manyfactors, including the size and weight of the wearer, and the activitythe wearer is engaged in when the measurement is taken. It is believedthat the lateral compressive forces associated with wearing sanitarynapkins may be in the range of slightly over 0 (e.g., about 0.01) toabout 2.5 psi., and more specifically, may be in the range of about 0.05to about 0.5 psi. If it is necessary to determine whether the spacingstructure 44 will deform under such forces, the following procedure maybe used. The procedure is referred to as the Lateral Compression Test.

Lateral Compression Test

Prior to and during the Lateral Compression Test, to ensure accuratereadings, the sanitary napkin 20 should not be bent, flexed, orotherwise handled in any manner that will affect the results of thetest. Therefore, the sanitary napkin 20 should typically only be testedby the following procedure once.

The sanitary napkin 20 is prepared for the test by removing any optionalcover strips 66 that may cover any adhesive attachment means 64 used foraffixing the sanitary napkin 20 to the wearer's undergarments. This willeliminate the possibility of any excess stiffness being imparted to thesanitary napkin 20 by the cover strip 66 that would not ordinarily bepresent when the sanitary napkin 20 is worn. The adhesive of theattachment means 64 may be sprinkled with corn starch or baby powder toeliminate as much as possible the tackiness of the adhesive so that theadhesive will not stick to any of the testing equipment.

The sanitary napkin 20 is then placed body surface 20a up in a suitabletesting device (possibly an Instron testing apparatus) that is capableof exerting lateral compressive forces inward from the longitudinaledges 22 of the sanitary napkin 20. The testing apparatus should beequipped with opposed arms that are capable of horizontal movementtoward each other. Each arm should have a clamp on the end. The armsshould move so that the clamps are able to exert compressive forces in asingle plane, and along the same line so that the sanitary napkin 20will not be subjected to bending or shearing forces. The clamps shouldbe arranged so that each of the portions of the sanitary napkin 20 thatare clamped will be held at an angle that is turned approximately 30°downward from horizontal.

The sanitary napkin 20 is then clamped in place in the testing device.The clamps should be affixed so that they grip the sanitary napkin 20inward (i.e., toward the principal longitudinal centerline l₁) of thelongitudinal edges 22 of the sanitary napkin 20 and the core 36, justoutside of the longitudinal edges 44f of the spacing structure 44. Theclamps should be applied so that they are in the region of thetransverse centerline t₂ of the spacing structure 44. The appropriatecompressive forces are then applied, and the decoupling of the topsheet28 of the sanitary napkin 20 is noted, and the test is thus completed.

The spacing structure 44 used in the present invention should besufficiently resilient that the sides 52 will not collapse inward whenthe structure 44 is compressed by the lateral compressive forces appliedby the wearer's thighs. The degree of resiliency, however, should besuch that the structure 44 will not resist deformation, but will utilizethe compressive forces to deform and improve contact of the sanitarynapkin 20 with the wearer's body. The spacing structure 44 itself canthus be of a configuration, due to folding or otherwise, that renders itresilient. Alternatively, or additionally, the spacing structure 44could be comprised of a material that has some degree of inherentresiliency. Preferably, the latter is the case. Most preferably, thematerial which comprises the spacing structure 44 is not only resilient,but is also wet resilient so the spacing structure 44 will not collapsewhen the sanitary napkin 20 is wetted by exudates.

The spacing structure 44 can be made of any suitable material. Thematerial used for the spacing structure 44 will normally be a thin sheetof flexible, liquid pervious material. Alternatively, the spacingstructure 44 can be comprised of a composite of two or more layers offlexible, liquid pervious material. The material used to construct thespacing structure 44 must be such that when it is folded, it will behavein the manner specified above. The material used to construct thespacing structure 44 should also be soft and non-irritating to thewearer when the spacing structure 44 deforms under the topsheet 28.Suitable materials for use in the spacing structure 44 include nonwovenfabrics, such as tissues. A suitable tissue can be made in accordancewith the patent issued to Trokhan, previously incorporated by reference.(Tissues will generally not by themselves, however, provide the spacingstructure 44 with the aforementioned wet resilient properties.) Plasticnets comprising water insoluble fiber forming polymers are alsosuitable. Suitable polymers for such nets include polyolefines, such aspolypropylene, propylene-ethylene copolymers and high densitypolyethelene, polyamides and polyesters.

Preferably, the spacing structure 44 is also absorbent. It is especiallydesirable for the spacing structure 44 to be absorbent if the topsheet28 is made of an apertured film which is coated with a surfactant (inaccordance with one suitable topsheet described above). If such amaterial is used for the topsheet 28, the component positioned under thetopsheet 28 (e.g., the spacing structure 44) must be both absorbent andin contact with the topsheet 28 to establish the capillary gradientrequired to cause liquids to flow through the topsheet 28 toward theabsorbent core 36. A particularly preferred absorbent material for useas the spacing structure 44 is the spunlaced nonwoven fiber sheet knownas "SONTARA" that is described in Column 8 of the Osborn patentpreviously incorporated by reference herein.

The shape into which the spacing structure 44 deforms can vary, but thisshape should have rounded rather than sharp edges so the sanitary napkin20 will be comfortable to wear. Preferably, the overall sanitary napkin20 deforms into a W-shape similar to that shown in FIG. 4. As shown inFIG. 4, the spacing structure 44 forms the central portion of theW-shaped configuration. In addition, the portion of the sanitary napkin20 that is worn to the rear of the wearer should assume a configurationthat will fit at least partially into the wearer's gluteal groove (i.e.,groove between the buttocks).

The distance that the spacing structure 44 may space the topsheet 28away from the core 36 can vary. This invention is intended to includeabsorbent articles having a spacing structure 44 that may space thetopsheet 28 various different distances away from the core 36. Thedistance that the spacing structure 44 may space the topsheet 28 awayfrom the core 36 depends upon a number of factors. These include themanner in which the sanitary napkin 20 is worn, and the place at whichthe separation is measured. For instance, the distance the topsheet 28is spaced away from the core 36 would generally be greater in theportion of the sanitary napkin 20 which is aligned near the rear of thewearer since the spacing structure 44 will have more space to move inthe region of the wearer's gluteal groove.

Preferably, the spacing structure 44 may move the topsheet 28 apart fromthe core 36 a distance of up to about 6 centimeters, preferably, betweenabout 0.5 centimeters and about 4 centimeters. More preferably, thespacing structure 44 may move the topsheet 28 apart from the core 36 adistance of between about 1 centimeter and about 3 centimeters. Thepresent invention is intended to encompass sanitary napkins having aspacing structure which is capable of spacing the topsheet away from thecore when either the sanitary napkin or the spacing structure aresufficiently laterally compressed from the sides either by hand, or bymechanical means, regardless of whether such separation actually takesplace when the sanitary napkin is worn.

The amount of separation of the topsheet 28 from the core 36 may bemeasured by the following method, which is referred to as the TopsheetSeparation Test.

Topsheet Separation Test

The sanitary napkin 20 should be handled in accordance with theprocedure specified above in the Lateral Compression Test (with theexception of the step of applying corn starch or baby powder to coverthe adhesive of the attachment means 64).

The sanitary napkin 20 is first cut completely through in the transversedirection so that the cut passes approximately through the transversecenterline t₂ of the spacing structure 44. This will leave the sanitarynapkin 20 open at one end.

The garment side 30b of the backsheet 30 of either half of the sanitarynapkin 20 is then attached to a rigid, flat, planar surface using theattachment means 64 that is ordinarily provided for attaching thebacksheet 30 to the undergarment of the wearer. The backsheet 30 ismaintained in contact with and parallel to this surface. Either at thistime, or at any convenient time prior thereto, the core 36 and thebacksheet 30 of the sanitary napkin 20 are glued together or otherwiseaffixed in some suitable manner so that the topsheet 28 and spacingstructure 44 will be able to separate in the intended manner from thecore 36, but the core 36 will not be able to separate from the backsheet30.

The longitudinal centerline l₂ of the spacing structure 44 at the openend of the sanitary napkin 20 is then located. The portion of thespacing structure 44 located at the longitudinal centerline l₁ is thenraised or lifted in the Z-direction, that is, in a direction generallyperpendicular to the flat, planar surface. The spacing structure 44 maybe lifted from the flat, planar surface by inserting one end of a thin,rigid instrument (such as a rod) between the upper portion 46 of thespacing structure 44 and the core 36. For the purpose of this test, theinserted end of the rod should be inserted into the open endapproximately 1 cm. The other end of the rod is lifted away from theflat, planar surface while the inserted end of the rod is used to raisethe spacing structure 44.

The end of the rod is lifted away from the flat, planar surface untilthe spacing structure 44 is restrained from moving further withoutstretching the material comprising the spacing structure 44. After thespacing structure 44 is raised in this manner, the Z-direction distancebetween the core-facing side 28b of the topsheet 28 and the body-facingside 36a of the core 36 is measured perpendicular to the flat, planarsurface. A separate scale, oriented in the Z-direction and generallyperpendicular to the flat, planar surface, may be used for thismeasurement. The measurement is taken at the longitudinal positioncoincident with the transverse centerline t₂ of the spacing structure44. When the measurement is taken, the test is completed.

There are certain additional characteristics that may either be presentin alternative embodiments, or in preferred embodiments of the spacingstructure 44. Preferably, not only does the spacing structure 44 assumea convex upward configuration, but it also assumes a shape that conformsthe topsheet 28 to the shape of the wearer's labial tissue. It is evenmore preferable that the spacing structure 44 provide the sanitarynapkin 20 with a shape so that the topsheet 28 can work its way into thespace between the wearer's labial tissue. Still even more preferably,the properties of the spacing structure 44 should be such that thespacing structure 44 will cause the topsheet 28, which serves as thebody-contacting element of the sanitary napkin 20, to adjust its shapein conformity with the movement of the wearer when the wearer movesabout. For example, if the wearer's activities cause her legs to beclose to each other, the spacing structure 44 should be more compressedor assume a more upright shape than if her legs are apart. (That is, thespacing structure 44 should have an overall width measured in thetransverse direction that is less than the height of the spacingstructure 44 measured in the Z-direction.) Preferably, when the wearer'sactivities or movements cause her legs to move back apart, the spacingstructure 44 will assume a flatter shape (that is, the overall width ofthe spacing structure 44 will increase and the overall height willdecrease).

Preferably, the spacing structure 44 should also form a hollow shapewhen it is subjected to compressive forces. As used herein, the term"hollow" means having a cavity within. While not wishing to be bound byany particular theory, it is believed that a hollow shape will aid thespacing structure 44 in retaining its integrity when compressed. When itis said that the integrity of the spacing structure 44 is retained, itis meant that the lateral sides 52 of the spacing structure 44 will nothave as great a tendency to collapse inward. As shown in FIG. 5, shapeof the cavity 72 in longitudinal cross-section may be similar to that ofa tube. In transverse cross-section, the cavity 72 can have manydifferent configurations such as the irregularly-shaped configurationshown in FIG. 4. In addition to the configuration of the cavity 72 shownin FIG. 4, the configuration of the transverse cross-section of thecavity 72 could also be nearly circular, elliptical, or of differentconfigurations in other situations and in other embodiments. As shown inFIG. 4, the spacing structure 44 defines at least a portion of theperimeter of the cavity 72. As shown in FIG. 4, when the ends of thespacing structure 44 are spaced apart, a portion of the perimeter of thecavity 72 could also be formed by part of some other element, such as aportion of the core 36. The total length of the perimeter of the cavity72 will usually remain constant regardless of the shape of the spacingstructure 44, and regardless of whether the spacing structure 44 iscompressed or uncompressed.

In an alternative embodiment shown in FIG. 14, a tissue layer in theform of a sheet or strip 78 could be provided in the interior of thespacing structure 44 (that is, between the upper and lower portions 46and 48).

The spacing structure 44 can also be constructed in the general form ofthe resilient member described in UK Patent Application 2 168 612 A(discussed above), which patent application is hereby incorporated byreference herein. However, such a resilient member must be provided withseveral key characteristics that are not disclosed in the UK patentapplication. The resilient member must be of such a construction that itallows, not resists deformation. The resilient member must be of such aconfiguration and must be made out of materials which makes the sides ofthe member move inward, instead of springing back in response tolaterally compressive forces. The member must only tend to return to itsoriginal configuration when such forces are removed, if at all. Inaddition, the member must have an upper portion that spaces the topsheetof a sanitary napkin away from the core when the member is compressed.The member must also form a closed configuration. The longitudinal edgesof the folded strip should, thus, either be bonded together, or toanother component of a sanitary napkin (instead of being free andunattached as shown in the drawings of the UK patent application). Thematerial from which the strip is fashioned must be relatively soft sothat it will be comfortable for the wearer. Further, the member must besecured to the core in some manner (rather than being unsecured), sothat it will not shift in position.

The spacing structure 44 can also serve functions in addition to spacingthe topsheet 28 away from the absorbent core 36. For instance, thespacing structure 44 could act as a wicking layer to distribute absorbedfluids over a wider area of the absorbent core 36 to increase theabsorbent capacity of the sanitary napkin 20.

4. Optional Components of the Sanitary Napkin

The sanitary napkin 20 of the present invention may be provided withoptional additional components.

The sanitary napkin 20 of the present invention can be provided with oneor more absorbent layers that may be positioned between the absorbentcore 36 and either the topsheet 28, the backsheet 30, or both. As shownin FIG. 6, an absorbent layer, such as wicking layer 58, is positionedbetween the topsheet 28 and the absorbent core 36. This wicking layer 58may be referred to as a secondary topsheet (or "wipe acquisitionsheet"). In addition, in another alternative embodiment, the wickinglayer 58 could have the characteristics set forth above for the spacingstructure 44, and could serve as the spacing structure 44.

As illustrated in FIG. 2, a sanitary napkin 20 according to the presentinvention may further comprise a liquid impervious interliner 60 that isassociated with the core 36 and intermediate the core 36 and backsheet30. The interliner 60 serves as the first constraint for any bodilydischarges that may tend to migrate towards the backsheet 30. However,if the interliner 60 is omitted, or if any discharges penetrate theinterliner 60, such discharges should generally be intercepted andretained by the backsheet 30. The interliner 60 is generally coextensivewith and preferably generally registered with the core 36.

The interliner 60 may be joined to the core 36 across the entire surfacearea of the interliner 60, or any portion of the same. An arrangement inwhich the interliner 60 is joined to the core 36 across its entiresurface area, however, results in a sanitary napkin 20 of lowerflexibility. Preferably, only the periphery of the interliner 60 isjoined to the core 36. In a preferred embodiment shown in FIG. 2, theinterliner 60 is peripherally joined to the face 36b of the core 36which is oriented towards the backsheet 30. Even more preferably asshown in FIG. 15, the interliner 60 wraps the longitudinal edges 36c ofthe core 36 and is peripherally joined to body-facing side 36a of thecore 36 adjacent the longitudinal edges 36c of the core 36. Theinterliner 60 may be heat sealed or, preferably, adhesively joined tothe absorbent core 36. A suitable material for adhesively joining theinterliner 60 to the absorbent core 36 is two-sided surgical tape Number1524 made by the Minnesota Mining and Manufacturing Company of St. Paul,Minn.

The interliner 60 is preferably relatively thin, and flexible.Preferably, the interliner 60 has a thickness less than or equal to thatof the backsheet 30 so that when the sanitary napkin 20 is worn and thesanitary napkin articulates between the open and closed positions(described below), discretion in the form of quietness is provided forthe wearer. An interliner 60 having a thickness of no greater than about0.02 millimeters is suitable. If the interliner 60 is liquid impervious,it is not necessary that the backsheet 30 also be liquid impervious. Insuch an embodiment, the interliner 60 functions as a backsheet and thebacksheet 30 need only be liquid resistant. As used herein the term"liquid resistant" refers to the property of a material which impedesthe transport of liquids through and past such a material. The termliquid resistant includes liquid impervious materials. A suitableinterliner 60 may be made from the low density polyethylene material,described above, used for the backsheet 30 or from X-7644 low densitypolyethylene film sold by the Ethyl Corporation, Visqueen Division ofTerre Haute, Ind.

If desired, the sanitary napkin 20 may be additionally provided withflaps 62 that extend outwardly from each longitudinal edge 22 of thesanitary napkin 20. The flaps 62 may be made in accordance with theteachings of U.S. Pat. No. 4,589,876, issued May 20, 1986 to Van Tilburgand U.S. Pat. No. 4,687,478, issued Aug. 18, 1987 to Van Tilburg, whichpatents are incorporated herein by reference.

In addition, as shown in FIG. 2, the garment side 30b of the backsheet30 may include a means for attaching the sanitary napkin 20 to theundergarment of the wearer ("attaching means") 64. Preferred attachingmeans 64 may include mechanical fasteners or, more preferably, adhesivefastening means, such as a pressure sensitive adhesive. The pressuresensitive adhesive may be applied to the garment side 30b of thebacksheet 36 in two parallel strips or two symmetrically opposite,convex outwardly oriented strips. The strips of adhesive may be betweenabout 5 to about 35 millimeters in width. Preferably, the strips ofadhesive are sized and disposed so that in the crotch region of thesanitary napkin 20 the distance between the inside edges of the stripsis about 11 mm, and the distance between the outside edges of the stripsis about 60 mm. A definition of the term "crotch region" is contained inU.S. Pat. No. 4,690,680 issued to Higgins on Sep. 1, 1987, which patentis hereby incorporated by reference herein.

Alternatively, the adhesive may be applied to the backsheet 30 in agenerally centered rectangular patch (not shown) covering about 30 toabout 70 percent of the area of the garment side 30b of the backsheet30. In another alternative illustrated in FIGS. 1-3, the adhesive can belongitudinally centered and disposed near the distal end of each flap 62(i.e., the end of the flaps 62 farthest away from the principallongitudinal centerline 1 of the sanitary napkin 20). Suitable adhesivemay be that specified as 0.6 mil pass available from Century Adhesive asproduct number A305-4, or from Anchor Continental, Inc., 3 SigmaDivision, of Covington, Ohio.

5. Separation of the Second Set of Components

The second set of components that are capable of separation comprisesthe absorbent core 36 and the backsheet 30 of the sanitary napkin 20.The separation or decoupling of the core 36 from the backsheet 30 isfirst shown in FIGS. 4 and 5 of the drawings.

In viewing the drawings, particularly FIGS. 4 and 5, it should initiallybe understood that the drawings are merely intended to be approximaterepresentations of the configurations that the sanitary napkin 20 maytake when it is worn. Thus, the compressed configuration of the sanitarynapkin 20 may be different from the specific configurations shown in thedrawings. The separation of the components may also occur in manners inaddition to those shown in the drawings. The scope of the presentinvention includes all of these other configurations and manners ofseparation. In addition, it should also be understood that the size ofvarious components of the sanitary napkin 20 may be slightly exaggeratedin the drawings. This has been done to better show the deformation ofthe spacing structure 44 and to more clearly show the separation of thecomponents of the sanitary napkin 20.

The separation of the core 36 from the backsheet 30 may alternatively bethought of as a separation of the topsheet 28 from the backsheet 30 asdescribed in U.S. patent application Ser. No. 07/429,252 entitled"Decoupled Sanitary Napkin", filed in the name of Osborn, et al. on Oct.27, 1989, which is hereby incorporated by reference herein. Theseparation may be viewed in such a manner because if the core 36separates from the backsheet 30, the topsheet 28 (being disposed on theother side of the core 36) will also separate from the backsheet 30.Regardless of how the separation from the backsheet 30 is thought of, itis believed that such separation is useful in providing a sanitarynapkin that can be attached to the undergarment of the wearer that willalso maintain a constant position with respect to the body of the wearereven though, as noted above, when the wearer moves about the wearer'sundergarments may not always move in exactly the same way as thewearer's body.

In addition, by separating the topsheet 28 and core 36 from thebacksheet 30, the flexibility of the portion of the sanitary napkin 20which is adjacent to and conforms to the wearer's body is enhanced andincreased. This occurs because the stiffness imparted by the backsheet30, and any associated components, will be generally less noticeable,due to these subcomponents being decoupled and further from the body ofthe wearer.

The separation of the core 36 from the backsheet 30 is made possible bythe manner in which the sanitary napkin 20 is constructed. Specifically,the separation occurs because of the way the core 36 is joined to thebacksheet 30. The core 36 is joined to the backsheet 30 along thelongitudinal edges 36c of the core 36. The core 36 may also be Joined tothe backsheet 30 along at least one transverse juncture 25a. Thetransverse juncture 25a can be a region such as a line or an edge. Thecore 36 is generally otherwise unattached to the backsheet 30 betweenits longitudinal edges 36c and at at least one end 24 of the sanitarynapkin 20. The unattached portion of the core 36 is generally designated36'. The unattached portion 36' of the core 36 may move apart from thebacksheet 30. Typically, the transverse juncture 25a is located in theportion of the sanitary napkin 20 that will be to the front of thewearer when the sanitary napkin 20 is worn. As illustrated in FIGS. 1-3,the transverse juncture 25a may be generally coincident with an end edge24, such as the front end edge 24a of the sanitary napkin 20. The endedge 24 at which the transverse juncture 25a is located may be referredto as the "joined end edge". The other end edge is the "unattached endedge" 25b. Typically, the unattached end edge 25b is oriented towardsthe rear of the wearer when the sanitary napkin 20 is worn (i.e., it islocated at end edge 24b ).

The definitions of several terms are useful in understanding the joinderof the components shown in the drawings. As used herein the term"joined" refers to the condition where a first member or component isattached, or connected, to a second member or component either directlyor indirectly. An "indirect" connection occurs where the first member orcomponent is attached or connected to an intermediate member orcomponent which in turn is attached or connected to the second member orcomponent. The relationship between the first and second Joined membersor components is intended to remain for the life of the members orcomponents. As used herein the term "unattached" refers to the conditionwhere two members or components are not joined or otherwise intended toremain in contacting and adjacent relationship during the useful life ofthe disposable absorbent article. The term "affixed" refers to atemporary contacting relationship between two members or components ofthe sanitary napkin 20. As used herein, the term "associated" comprisesintegral, joined, affixed, indirectly and weakly linked relationships.

As shown in FIGS. 4 and 5, the absorbent core 36 is indirectly connectedto the backsheet 30. In the embodiment shown in FIGS. 4 and 5, the core36 is connected to the optional interliner 60, and the optionalinterliner 60 is connected to the backsheet 30 as described above (i.e.,joined at the longitudinal edges and at a transverse juncture 25a). Ifthere is no optional interliner 60, as shown in FIG. 16, the core 36could be directly connected to the backsheet 30 along its longitudinaledges 36c and at a transverse juncture 25a.

As noted above, the transverse juncture 25a may be referred to as anedge. The transverse juncture 25a is an edge the sense that it may beviewed as a line that is formed by the intersection of two planes, suchas the plane defined by the core 36, and the plane formed by thebacksheet 30. The transverse juncture 25a functions like a hinge,allowing parts of the sanitary napkin 20 (e.g., the topsheet 28, thecore 36, and the interliner 60) to articulate with respect to thebacksheet 30 about the joined end edge 24a. As illustrated by comparingFIGS. 3 and 5, the sanitary napkin 20 articulates between a closedposition and an open position. In the "closed position" of FIG. 3, theunattached end edges, 36d' and 30d', of the core 36 and backsheet 30 aregenerally proximate and preferably adjacent. In the "open position" ofFIG. 5, the unattached end edges, 36d' and 30d', of the core 36 andbacksheet 30 are separated in the Z-direction, relative to each other,from their respective closed position locations.

As shown in FIGS. 4 and 5, the sanitary napkin 20 has a means forcontrolling the separation of the core 36 from the backsheet 30. Themeans for controlling the separation of the core 36 from the backsheet30 prevents the sanitary napkin 20 from unintended gross deformationsand from exceeding the open position. As used herein a "means forcontrolling the separation of the core from the backsheet" is anycomponent which limits the relative Z-direction separation of the core36 from the backsheet 30.

One suitable means for controlling the amount of separation of the core36 from the backsheet 30 is by the use of a material having alongitudinally-oriented pleat (a "pleated material") 68 to join the core36 directly or indirectly to the backsheet 30. The pleated material 68typically, but not necessarily, has a length in the longitudinaldirection generally equivalent to the longitudinal dimension of theshorter of the core 36 and the backsheet 30. The pleated material 68also generally has at least one longitudinally oriented fold line 70, sothat dual, or more than two, Z-direction layers of the material areprovided along the length of the fold line 70. The pleated material 68may be an extension of the topsheet 28, an extension of the backsheet30, or a separate piece of material having one end joined directly orindirectly to the core 36 and the other end joined to the backsheet 30.Preferably, two pieces of material, each having longitudinally orientedpleats are provided, one near each longitudinal edge 36c of theabsorbent core 36. In addition, a foreign lamina or material may also beinterposed between the dual layers of the pleated material 68.

As shown in FIG. 2, a preferred longitudinally oriented pleated material68 is provided by an extension of the topsheet 28. In the embodimentshown in FIG. 2, the topsheet 28 is in a C-folded configuration. Thelongitudinal ends 28e of the sheet that comprises the topsheet 28 arefolded under the central portion of the topsheet 28 so they arelaterally inboard of the longitudinal edges 36c of the absorbent core36, and are joined to the backsheet 30. Joining may either beaccomplished by heat sealing or adhesive bonding. The Number 1524surgical tape sold by the Minnesota Mining and Manufacturing Company issuitable for this purpose. The longitudinally oriented pleated material68 may have a fold line 70 between the longitudinal end 28e of the sheetthat is joined to the backsheet 30 and the corresponding layer ofmaterial, which forms part of the longitudinally oriented pleat that ispositioned directly above the longitudinal end 28e.

As shown in FIG. 2, the longitudinal ends 28e of the topsheet 28 arefolded inwardly (i.e., towards the longitudinal centerline l₁)underneath the core 36 and joined to the backsheet 30. In the closedposition the C-folded sheet is collapsed, and the pleats of the sheetextend transversely and have material that is flaccid in theZ-direction. When the sanitary napkin 20 is articulated to the openposition, the fold lines 70 of the longitudinally oriented pleatedmaterial 68 are lifted away from the backsheet 30 in the Z-direction.This removes the slack from the flaccid material and allows separationin the Z-direction until constrained when the pleats are fully extended.Preferably, the width of the pleats (that is, the dimension measured inthe transverse direction between a longitudinal ends 28e of the sheetand the fold line 70, or between the fold lines of the pleat, if thereis more than one pleat) ranges from about 2 millimeters to about 15millimeters, and is preferably about 5 millimeters to about 8millimeters.

Another suitable means for controlling the separation of the core 36from the backsheet 30 is by use of a material having accordion stylelongitudinally oriented pleats 68 as shown in FIG. 17. Such an accordianstyle pleated material 68 has two distal ends, a central sectiongenerally centered between the distal ends, and a plurality oflongitudinally oriented fold lines 70 defining the individual pleats.The accordian style pleat can be provided by a piece of material that iseither an extension of the topsheet 28 or of the backsheet 30.Alternatively, the accordian pleat could be formed from a separate pieceof material that has one end affixed either directly or indirectly tothe core 36, and the other end affixed to the core-facing side 30a ofthe backsheet 30. An accordion pleat provides the advantage thatrelatively large Z-direction separation is feasible, without requiringthe pleated section of the material to have an excessive lateral width.

The material having the C-fold, accordion style pleat, or otherlongitudinally oriented pleat 68 may be longitudinally tapered, or, forease of manufacture, as shown in the drawings, of a longitudinallyconstant geometry. If longitudinally tapered, the material having theC-fold or accordion style pleat may provide a generally uniformconstraint along the entire longitudinal distance between the end edgesof the core 36 and backsheet 30 (36d' and 30d', respectively) which aresubtended by the pleated material. If a material with a constantgeometry pleat is selected, the width of the C-fold or accordion stylepleat at the unattached end edges, 36d' and 30d', of the core 36 andbacksheet 30 will control the maximum Z-direction separation, and hencedecoupling, of the core 36 from the backsheet 30.

The longitudinally oriented pleated material 68 may be of anylongitudinal dimension desired, so long as the material 68 can resistZ-directional separation forces and prevent the sanitary napkin 20 fromarticulating past the intended open position. For instance, the pleatedmaterial 68 may be significantly shorter in longitudinal dimension thanother components of the sanitary napkin 20, such as the core 36 and thebacksheet 30. It is important, however, that the longitudinally orientedpleated material 68 be longitudinally registered with (i.e.,approximately the same distance away from the principal transversecenterline t₁) that portion of the sanitary napkin 20 at which it isdesired to control the Z-direction separation. In other words, if it isdesirable to control the separation at the back end edge 24b of thesanitary napkin 20, or at the principal transverse centerline t₁, thematerial having the longitudinally oriented pleat 68 should berespectively positioned adjacent the back end edge 24b and 30d, or nearthe principal transverse centerline t₁ of the sanitary napkin 20. Inaddition to the single piece of pleated material on each side of thesanitary napkin 20 shown in the drawings, if desired, discrete pieces ofmaterial having longitudinally oriented pleats may be provided at bothof the locations described above, or at other locations.

As shown in FIG. 18, the transverse juncture 25a where the core 36 andbacksheet 30 are Joined need not be coincident with and end 24 of thesanitary napkin 20. As shown in FIG. 18, the transverse Juncture 25a maybe longitudinally offset inward (i.e., inset) towards the principaltransverse centerline t_(l). If such an embodiment is selected, thetransverse juncture 25a should be inset from the end 24 of the sanitarynapkin 20 at least about one-fifth of the longitudinal dimension of thesanitary napkin 20. Preferably, the transverse juncture 25a islongitudinally positioned so that the decoupling of the core 36 from thebacksheet 30 will conform the sanitary napkin 20 to the wearer'sanatomy. Thus, the transverse juncture 25a should be located so thattopsheet 28 and core 36 may lift and conform with the wearer's labialtissue in the front portion of the sanitary napkin 20 to more readilyintercept menses upon discharge, and the rear portion of the sanitarynapkin 20 will lift to fit into the wearer's gluteal groove. Aparticularly preferred location of the transverse juncture 25a isapproximately one-third of the longitudinal distance from either end 24.

As shown in FIG. 18, the arrangement described above provides a sanitarynapkin 20 having two unattached end edges 25b and 25b'. The twounattached end edges 25b and 25b' can independently articulate and movein the Z-direction. Thus, the portions of the sanitary napkin 20(particularly the unattached end edges 25b and 25b') located both infront of and behind the transverse juncture 25a may be separated in theZ-direction.

It will be apparent to one skilled in the art that the transversejuncture 25a, regardless of its longitudinal position, need not beJoined across the entire width of the sanitary napkin 20. The core 36and backsheet 30 may be joined only in the region of the longitudinaledges 36c of the core 36 as illustrated in FIG. 2. In other alternativeembodiments, the core 36 may be intermittently joined across thetransverse width of the sanitary napkin 20.

If desired, the transverse Juncture 25a may be formed by the opposedforces of the body and undergarment against the sanitary napkin 20. Thisembodiment is more effectively utilized with a relatively tightlyfitting undergarment. Such an embodiment (not shown) resembles an opentube and has no transverse juncture 25a where the topsheet 28 andbacksheet 30 are Joined. If such an embodiment is selected, it shouldhave lesser Z-direction separation than the embodiments described above,otherwise excessive lateral shifting of one component of the sanitarynapkin 20 relative to the other components may occur. This lesserseparation may be accomplished, for example, by providing longitudinallyoriented pleats 68 with a lesser width. A longitudinally oriented pleat68 having width of about 3 millimeters is suitable for such anembodiment.

A sanitary napkin 20 according to the present invention may furthercomprise a transversely-oriented material having a transverse pleat 80(shown in FIG. 19) that connects the core 36 and the backsheet 30 at theunattached end edge 25b. The material having a transverse pleat ispreferably made of a liquid impervious panel that has one end Joined tothe garment-facing side 36b of the core 36 and one end joined to thecore-facing side 30a of the backsheet 30. If desired, the longitudinaledges of the material 80 having the the transverse pleat may be joinedto the means for controlling the separation of the core 36 and backsheet30. The material having the transverse pleat 80 provides the advantagethat menses which may exceed the absorbent capacity of the core 36 orwhich migrates longitudinally from or beyond the unattached end edge 25bof the napkin will be retained in the sanitary napkin 20.

In a less elegant embodiment shown in FIG. 20, the means for controllingthe separation of the core 36 from the backsheet 30 of the sanitarynapkin 20 may simply comprise flaccid material 82 joining the core 36 tothe backsheet 30. As used herein, "flaccid material" refers to materialintended to be slack in the Z-direction while the sanitary napkin 20 isin the closed position and allows for movement of such material andassociated components in the Z-direction. In such an embodiment, anexcess of material of one of the backsheet 30 or topsheet 28 may bejoined to the other, or to the core 36 either directly or indirectly.Separation in the Z-direction may occur until the core 36 and thebacksheet 30 are restrained from further separating by the flaccidmaterial 82 becoming taut. Such an embodiment is similar to thosedescribed above, except the means for controlling the separation of thecore 36 and backsheet 30 assumes random, undefined forms, which are notpredetermined, when the sanitary napkin 20 is in the closed position.This is in contrast to the aforementioned embodiments where the meansfor controlling the separation of the core 36 from the backsheet 30 haveprecise, repeatable and predetermined geometries for both the closed andopened positions.

The amount that the core 36 can separate from the backsheet 30 can vary.For a sanitary napkin 20 having a topsheet 28 longitudinal dimension ofbetween about 13 to about 35 centimeters, the unattached end edges 25band 25b' should have a maximum separation in the Z-direction of about 1to about 6 centimeters, and preferably about 3 to 4 centimeters. If themaximum Z-direction separation is less, the desired decoupling of thesanitary napkin 20 components may not occur. This could result incontact not being maintained between the undergarment and the backsheet30 and between the body of the wearer and the topsheet 28. Conversely,if a greater maximum Z-direction separation occurs at the unattached endedges 25b and 25b', the sanitary napkin 20 may appear limp and beuncomfortable to wear. Further, a greater Z-direction separation couldcause collapsing in the X-Y plane, particularly in the transversedirection, thereby causing the core 36 and backsheet 30 of the sanitarynapkin 20 to become misaligned.

In certain embodiments, particularly those where the transverse juncture25a is at one of the ends 24 of the sanitary napkin 20, the magnitude ofthe Z-direction separation of the longitudinally centered portion of thesanitary napkin 20 (which is intended to be placed in the proximity ofor registered with the vaginal opening), is also important and should beconsidered. Frequently, the sanitary napkin 20 is isomericallydistributed about and longitudinally centered on the vagina of thewearer, (i.e., the principal transverse centerline t₁ of the sanitarynapkin 20 will be registered with the vagina). If so registered, theZ-direction separation at the principal transverse centerline t₁ will beabout one-half of the Z-direction separation at the unattached end edge,such as 25b. Thus, the separation at the principal transverse centerlinet₁ may be from about 0.5 centimeters to about 6 centimeters, and ispreferably about 0.5 to 3 centimeters, and more preferably about 1.5 to2 centimeters.

In addition, if the sanitary napkin 20 has two sets of components thatare capable of separating, the separation of the core 36 from thebacksheet 30 may be somewhat less than the amounts discussed above whenthe sanitary napkin 20 is in use. It is believed that in use, the totalseparation between both sets of components may be in the above ranges.The total separation between both sets of components is limited by thedistance between the wearer's body and the wearer's undergarments. Whenthe sanitary napkin 20 is worn, part of the space between the wearer'sbody and the wearer's undergarments will be occupied by the spacecreated by the separation of the topsheet 28 from the core 36. Theremainder will be occupied by the space created by the separation of thecore 36 from the backsheet 30.

The amount of separation of the unattached end edges 36d' and 30d' ofthe core 36 and backsheet 30 may be measured by the following twomethods.

Core/Backsheet Separation Tests

Z-Direction separation Test

In the first method, the sanitary napkin 20 is attached to a rigid,flat, planar surface in the same manner described above for measuringthe separation of the topsheet 28 from the core 36. The core 36,however, is not affixed to the backsheet 30. The intersection of theprincipal longitudinal centerline l₁ and unattached end edge 25b or 25b'of the sanitary napkin 20 is then located. The portion of the core 36located at this intersection is raised or lifted in the Z-directionuntil the core 36 is fully articulated from the flat, planar surface andthe sanitary napkin 20 is in the open position. The core 36 is liftedfrom the flat, planar surface by inserting a thin blade (such as a ruleor scale about 2.5 centimeters wide and about 1 millimeter thick)between the core 36 and backsheet 30. The end of the blade is insertedto the transverse juncture 25a. The opposite end of the blade is liftedaway from the flat, planar surface while maintaining the inserted end ofthe blade on the backsheet 30 and adjacent the transverse Juncture 25a.

The unattached end edge 36d' of the core 36 travels in an arc concavelyoriented towards the transverse juncture 25a and the flat, planarsurface. The topsheet 28 and core 36 may bow to a slightly concavedownward configuration, as the longitudinal center of the core 36 isbeing raised and the longitudinal edges of the topsheet 28 and core 36are restrained by the means for controlling the separation of the core36 from the backsheet 30.

The end of the blade is lifted away from the flat, planar surface untilthe sanitary napkin 20 is articulated to the open position. When theopen position is reached, the Z-direction distance between thecore-facing side 30a of the backsheet 30 and the body-facing side 36b ofthe core 36 is measured in a direction perpendicular to the flat, planarsurface. A separate scale, oriented in the Z-direction and generallyperpendicular the flat, planar surface, may be used for thismeasurement. The measurement is taken at the longitudinal position thatcoincides with the unattached end edges 25b or 25b' of the sanitarynapkin 20 when the sanitary napkin 20 is in the open position.

Included Angle Separation Test

Another measure of the desired separation of the core 36 and backsheet30 is to determine the included angle α which the garment-facing side36b of the core 36 and the core-facing side 30a of the backsheet 30define when the sanitary napkin 20 is articulated to the open position.

The measurement of this included angle e may be accomplished in a mannersimilar to that described above for measuring the amount of Z-directionseparation of the core 36 and backsheet 30. The sanitary napkin 20 isaffixed, using the means 64 for attaching the sanitary napkin 20 to theundergarment of the wearer, to a rigid flat, planar surface. The core 36is articulated to the open position as described above. The amount ofZ-direction separation is measured, as described above. The distancetaken along the plane of the garment-facing side 36b of the core 36between the transverse juncture 25a and the unattached end edge 36d'along the principal longitudinal centerline l₁ is also measured.

The included angle α is then found by triangulating these twomeasurements. The included angle e is equivalent to the arcsin of themagnitude of the Z-direction separation divided by the distance betweenthe transverse juncture 25a and the unattached edge 36d' of the core 36.Preferably the included angle α of the sanitary napkin 20 is betweenabout 3° and about 60°, and more preferably between about 7° and about20°.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended Claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. An absorbent article having a principal longitudinal centerline, said absorbent article comprising:a liquid pervious topsheet; a liquid impervious backsheet joined to said topsheet; an absorbent core positioned between said topsheet and said backsheet; a liquid pervious spacing structure for moving said topsheet away from said core, said spacing structure comprising a sheet that is folded to form a tube, said spacing structure being positioned between said topsheet and said absorbent core and having an uncompressed configuration, a compressed configuration, a longitudinal centerline, a transverse centerline, and comprising an upper portion, a lower portion, and opposed lateral sides, wherein;said upper portion is positioned between said topsheet and said lower portion, and at least parts of said upper portion overlay parts of said lower portion when said spacing structure is in its uncompressed configuration, said lower portion is adjacent said core when said spacing structure is in its uncompressed configuration, and at least a section of said lower portion is connected to at least part of said core to define an attached section of said lower portion, andwhen said spacing structure is compressed from the sides, said opposed lateral sides may move inwardly toward said longitudinal centerline, resulting in at least some of said upper portion moving said topsheet away from said absorbent core.
 2. An absorbent article having a principal longitudinal centerline, said absorbent article comprising:a liquid pervious topsheet; a liquid impervious backsheet joined to said topsheet; an absorbent core positioned between said topsheet and said backsheet, said absorbent core at least partially comprising a liquid pervious spacing structure for moving at least part of said topsheet away from at least part of said backsheet, said spacing structure being positioned subjacent said topsheet and having an uncompressed configuration, a compressed configuration, a longitudinal centerline, a transverse centerline, and comprising an upper portion, a lower portion, and opposed lateral sides, wherein:said upper portion is positioned between said topsheet and said lower portion, and at least parts of said upper portion overlay parts of said lower portion when said spacing structure is in its uncompressed configuration, said lower portion is closer to said backsheet than said upper portion when said spacing structure is in its uncompressed configuration, and at least a section of said lower portion is adjacent to an underlying component, and when said spacing structure is compressed from the sides, said opposed lateral sides may move inwardly toward said longitudinal centerline, resulting in at least some of said upper portion moving said topsheet away from said underlying component.
 3. The absorbent article of claim 2 wherein said spacing structure comprises a folded sheet.
 4. The absorbent article of claim 3 wherein said sheet is folded about at least one longitudinal axis.
 5. The absorbent article of claim 4 wherein said sheet has at least two longitudinal folds.
 6. The absorbent article of claim 4 wherein said spacing structure has two longitudinal edges and two transverse edges, wherein said sheet has at least two longitudinal folds and said longitudinal folds are near the longitudinal edges of the spacing structure.
 7. The absorbent article of claim 6 wherein said sheet is folded into the configuration of the letter "C".
 8. The absorbent article of claim 6 wherein said folded sheet is a flattened tube.
 9. An absorbent article having a principal longitudinal centerline, said absorbent article comprising:a liquid pervious topsheet; a liquid impervious backsheet joined to said topsheet; an absorbent core positioned between said topsheet and said backsheet; a liquid pervious spacing structure for moving said topsheet away from said core, said spacing structure comprising a folded sheet that has two longitudinal edges, two transverse edges, and at least two longitudinal folds, and said longitudinal folds are near the longitudinal edges of the spacing structure, said spacing structure being positioned between said topsheet and said absorbent core, and having an uncompressed configuration, a compressed configuration, a longitudinal centerline, a transverse centerline, and comprising an upper portion, a lower portion, and opposed lateral sides, wherein;said upper portion is positioned between said topsheet and said lower portion, and at least parts of said upper portion overlay parts of said lower portion when said spacing structure is in its uncompressed configuration, said lower portion is adjacent said core when said spacing structure is in its uncompressed configuration, and at least a section of said lower portion is connected to at least part of said core to define an attached section of said lower portion, and when said spacing structure is compressed from the sides, said opposed lateral sides may move inwardly toward said longitudinal centerline, resulting in at least some of said upper portion moving said topsheet away from said absorbent core.
 10. The absorbent article of claim 9 wherein the longitudinal edges of said sheet are folded over one side of said sheet to overlap each other.
 11. The absorbent article of claim 9 wherein said spacing structure is comprised of more than one piece of material.
 12. The absorbent article of claim 9 further comprising at least one pervious layer positioned between said topsheet and said spacing structure so that said upper portion is adjacent a pervious layer, and when said spacing structure is compressed from the sides, at least some of said upper portion moves said pervious layer and said topsheet apart from said absorbent core.
 13. The absorbent article of claim 9 wherein said sheet is folded into the configuration of the letter "C".
 14. The absorbent article of claim 9 wherein said folded sheet is a flattened tube.
 15. The absorbent article of claims 9, 13, or 14, wherein said attached section of said lower portion of said spacing structure is connected to said core by a spacing structure securement means that is generally oriented in the longitudinal direction.
 16. The absorbent article of claim 15 wherein said spacing structure securement means comprises an adhesive.
 17. The absorbent article of claim 15 wherein said spacing structure securement means comprises at least one longitudinally oriented region of adhesive that is in the region of the principal longitudinal centerline of said sanitary napkin.
 18. A sanitary napkins according to claim
 15. 19. The sanitary napkin of claim 18 wherein said spacing structure is also absorbent. 